The present disclosure relates to a multilayer ceramic capacitor and a board having the same.
A multilayer ceramic capacitor (MLCC) has advantages including a small size, high capacitance, ease of mounting, and the like.
Multilayer ceramic capacitors may be mounted on the circuit boards of image display devices such as a liquid crystal display (LCD), a plasma display panel (PDP), and those of several types of electronic products such as computers, smartphones, and cellular phones to serve to charge or discharge electricity.
A power supply for a central processing unit (CPU) of a computer may cause voltage noise due to a rapid change in a load current when a low voltage is provided.
Therefore, in the power supply, the multilayer ceramic capacitor may be used for the purpose of decoupling to suppress such voltage noise.
As the operating frequency of the multilayer ceramic capacitor for decoupling has recently increased, however, a lower equivalent series inductance (ESL) value is required.
Furthermore, when an equivalent series resistance (ESR) value of the multilayer ceramic capacitor is lower than a desired level, an impedance peak in a parallel resonance frequency generated due to ESL of the multilayer ceramic capacitor and plane capacitance of a microprocessor package may be increased, and impedance at a series resonance frequency of the multilayer ceramic capacitor may be excessively decreased.
Therefore, ESR characteristics of the multilayer ceramic capacitor for decoupling need to be adjusted so that flat impedance characteristics may be implemented in a power distribution network and power can be supplied in a more stable manner.
One method for adjusting ESR characteristics includes forming external and internal electrodes of materials having high electrical resistance.
In this case, a multilayer ceramic capacitor having high ESR characteristics while maintaining a low ESL structure according to the related art may be provided.
In the case in which the external electrodes are formed of the high resistance material, however, a current concentration phenomenon may occur due to a pin hole phenomenon, which may cause localized heat spots, and in the case in which the internal electrodes are formed of the high resistance material, the material of the internal electrode should be continuously changed for matching with a ceramic material to allow for high capacity.
Recently, mobile terminals such as tablet personal computers (PCs), ultrabooks, or the like have been rapidly developed, and microprocessors have also become small, highly integrated products.
Therefore, an area of the circuit board is reduced, and a mounting space of a decoupling capacitor is also limited.